Breathing Easy About IAQ

CONSULTING-SPECIFYING ENGINEER (CSE): When it comes to convincing facility owners to accept a design that optimizes indoor air quality (IAQ), the stumbling blocks are often budget and first cost. How does one educate owners about life-cycle costing, payback periods and the long-term benefits of more expensive systems that guarantee the best IAQ? BURROUGHS: We must go beyond mathematics and pres...

By Scott Siddens, Senior Editor and Barbara Horwitz, Associate Editor

11/01/2002

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CONSULTING-SPECIFYING ENGINEER (CSE): When it comes to convincing facility owners to accept a design that optimizes indoor air quality (IAQ), the stumbling blocks are often budget and first cost. How does one educate owners about life-cycle costing, payback periods and the long-term benefits of more expensive systems that guarantee the best IAQ?

BURROUGHS : We must go beyond mathematics and present science and experience as motivators for higher quality first-purchase decisions. There are many negative consequences resulting from poor IAQ-related decisions—mostly in the form of litigation or massive reconstructive remediation. Either of these outcomes negates any first-cost savings.

LIETTE : In today's world, it is essential that engineers be educators. To prepare for this role, the engineer must develop a detailed file of life-cycle analyses that can be supported with real data obtained from completed installations. It has become increasingly difficult to present building owners with the pros and cons of all the HVAC systems available today. It also requires coordination and cooperation with the architect for systems that impact basic floor plan and structural design—such as underfloor air systems.

PORT : And it's imperative to understand to whom you're making the presentation. This establishes the strategy. For example, if the audience is financial, then one should use case studies that illustrate long-term cost analysis and benefits; if it's operations, then a focus on maintenance and housekeeping benefits should work.

BURROUGHS : That's a good point. A big part of the problem is a disconnect between the finance/design and operational teams. In other words, the people who make first-cost decisions don't often interface with the management team that must cope with the resulting IAQ and performance problems.

CSE: Can you briefly explain why there are so many cases of bad IAQ, particularly mold-related ones?

BURROUGHS : The high incidence of mold, which is receiving so much press right now, might be the result of poor building envelope design and construction—which can result in water intrusion—combined with poorly sized HVAC equipment that is not coping with the resulting high levels of humidity. The result is litigation, mitigation and severe impairment of both the structure and the asset value of the property—whether a residence, hotel or office building. When this sequence occurs in a health-care facility, the results can be tragic, with the possibility of nosocomial disease outbreaks from pathogenic fungi.

CSE: Are there any other causes?

BURROUGHS : Lack of proper commissioning in the construction process is another problem. All of the major sick-building syndrome cases among public buildings could have been avoided by appropriate commissioning, which is often deleted because of first cost. Even worse, it's assumed that commissioning is being performed as part of the contractor price. [See "Maintaining a Successful IAQ Program," p. 28.]

PORT : In my experience, one of the most promising technologies for improving and maintaining acceptable IAQ is thermal-recovery. But more important than the system is a proactive training program for a facility's maintenance personnel and occupants.

LIETTE : Energy-recovery does offer a direct means for increasing the amount of ventilation air into any given space. Obviously, more thought is required to make sure the ventilation air, if entering through a central air system, is actually getting to the occupied spaces.

Another promising technology is underfloor air distribution. These systems provide the opportunity to impact the true "occupied" zone in occupied spaces, but it does not offer any better means for assuring that the ventilation air entering the building through a central air system is actually getting to the occupied space. Unfortunately, construction budgets will continue to limit the use of underfloor systems.

Ultraviolet light-based devices are getting a lot of attention, but they are only addressing a small portion of the IAQ issue and will only be considered as a part of an entire system. Good filtration with adequate dilution will continue to be prevalent over UV devices.

BURROUGHS : In my opinion, "silver bullet" technologies like underfloor air, energy-recovery ventilators (ERVs) and even UV devices are not particularly good IAQ solutions. From a geographic standpoint, ERVs only have a very limited applicability. Underfloor air distribution has yet to prove it can create acceptable comfort levels and has serious ventilation efficiency and contaminant control issues. UV is also limited in its ability to control microbials in a fast moving airstream.

The best technologies for good IAQ are the ones that are readily available but that we don't apply well: humidity control and water management; air pathway control; proper ventilation; air cleaning and filtration; and proper and timely maintenance. Keeping a system dry and clean is the most logical and effective means of attaining good IAQ. None of the silver bullets that are being so loudly marketed will work without these basics.

CSE: How do you deal with retrofit situations, where the strategies outlined by Mr. Burroughs were not originally implemented?

LIETTE : We've found the implementation of central plant air systems is proving to be effective in either retrofits or new construction. A central plant with air handling units and variable-volume distribution offers the best specific control of the quality of air delivered to occupied spaces. Such systems also offer the greatest opportunity for energy-related cost savings. Unfortunately, some existing facilities will drive the retrofit toward a more aged design concept that includes fan coils for each occupied space.

PORT : Thermal-recovery systems are the easiest to add into, without having to redesign or rebuild the existing system.

BURROUGHS : Classic IAQ retrofit case studies can be found by examining Florida's court houses. Many of these structures had to be rebuilt from the outside in and then the inside out—at a cost that was a multiplier of the first cost. The problem with IAQ issues is that they occur after the construction process is over—and it is difficult to go back and repair. When you bake a cake and leave out the sugar, adding frosting does little to repair the damage. The only system that can be easily upgraded is filtration and air cleaning—and even then, modifications for room and pressure drop must sometimes be added.

CSE: A major contributor to bad IAQ, of course, is mold. While a legitimate concern, in your opinion, has it been hyped to the point where perhaps attention to other contributors, such as volatile organic compounds (VOCs), has been neglected?

PORT : The media has definitely taken a few mold-related incidents and blown them way out of proportion—but not to the point of neglecting other issues. In my experience, an initial consultation, combined with a little teaching, usually leads to a better awareness of total IAQ issues and implementation of a management program.

BURROUGHS : I agree. There is no question that mold issues have been overhyped. We as a species have been coexisting with fungi throughout history. And one Stachybotrys spore is not going to destroy human life on earth. But when mold is a significant issue, there are many elements involved—structural, furnishings, decorations, HVAC and building envelope. And the problem gets worse every day.

As far as VOCs, they tend to go away after a building vents and ages, unless reintroduced by a specific and manageable transient activity or entrained through air pathway introduction. The basic difference is that mold in a building is systemic, while VOCs are symptomatic of specific correctable sources.

LIETTE : VOCs have not necessarily been neglected in the recent onslaught of potential mold and microbe discoveries. It's more a case that someone has taken extreme steps to raise a public concern over potential or perceived mold issues that may or may not be harmful to our way of life. Please understand that if a patch or spot of mold is discovered, all necessary precautions should be taken to mitigate the issue and preventive measures taken to avoid a similar condition in the building. If we keep our eye on the ventilation ball, a number of perceived mold issues would not develop and the occupants of our buildings would be comfortable.

CSE: Engineers are always at the center of the IAQ debate. How can HVAC engineers work with architects, owners and contractors to produce a facility with a 'high IAQ'?

BURROUGHS : The truth is that the engineer is seldom involved in the systems or decisions that lead to IAQ failure. Furthermore, the fee structure for engineering is so constrained that paying attention to IAQ and all its ramifications is not practical. So, not all engineers are that savvy about IAQ because they can't afford to be.

Secondly, engineers are not the lead decision-makers—even though they are named in most of the suits. They take the building that they are handed—with paltry room for mechanical systems—and try to make the most with it. The other root factor is that contractors are motivated to take cost out of a job and often the result is that hundreds, if not thousands of schools in this country have IAQ problems. They are products of this process.

PORT : If there is to be change, it must start with the pre-construction planning process. Organizations such as the U.S. Green Buildings Council have become involved in the initial planning of new construction. Engineers and architects should propose a team approach to design a building that achieves good IAQ.

LIETTE : All parties must be engaged and be true to a common goal. That is a global requirement to which fully staffed A/E firms have already resolved. The entire team must address the specifics of a project during the outlining of project expectations. If high IAQ is included in the expectations for the project, then the architect and HVAC engineer must be communicating common agendas. Building areas and budget will be needed for the HVAC system, but the system design can be creative in order to allow for the architectural expression of the design to take place. Communication is key.

Maintaining a Successful IAQ Program

Even a well-designed IAQ program can leave occupants gasping if the building's maintenance staff isn't well trained in its operation.

"The end of the commissioning process should include turning over thorough documentation and setting up specific training for operating personnel," says H.E. Barney Burroughs, president, Building Wellness Consultancy, Alpharetta, Ga. "Proper documentation—meaning written specifics as to how to operate, trouble shoot, repair and maintain the systems—and formal training of the right people are essential."

Burroughs recommends the new addendum on O&M in the ASHRAE Standard 62-2001 as a good starting document for commissioning teams.

Furthermore, Andrew Port, project manager for Environmental Health & Safety, The Whitman Companies Inc., East Brunswick, N.J., says the commissioning any HVAC system should involve maintenance personnel from the start.

"It is imperative that these people understand the various components of the system and their effect on air quality," he says.

"It is essential that future staff is included in the setting of goals and expectations in order to begin taking ownership in the operation of the proposed new facility," he says.

For example, Liette recommends that a building's staff be involved with installation inspections during construction and that they participate in system startups and testing/balancing.

"Understanding those components offers the staff a leg up before starting final training on the operation of all the building systems," he says.

The building's occupants also play a role in the continued success of an IAQ program.

"Their understanding of the consequences of their actions, combined with their ability to notify building management of conditions or incidents, makes them the first line of an IAQ program," Port says.